A 96-well plate has been precoated with Herpes simplex virus Type 1 antigens to bind cognate antibodies. Controls or test samples are added to the wells and incubated. Following washing, a horseradish peroxidase (HRP) labelled anti-Human IgM conjugate is added to the wells, which binds to the immobilized Herpes simplex virus Type 1-specific antibodies. TMB is then catalyzed by the HRP to produce a blue color product that changes to yellow after adding an acidic stop solution. The density of yellow coloration is directly proportional to the amount of Herpes simplex virus Type 1 IgM sample captured in plate.